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From: spolsky-joel@cs.yale.edu (Joel Spolsky)
Newsgroups: comp.windows.ms.programmer
Subject: Re: Linked list in Windows
Message-ID: <27221@cs.yale.edu>
Date: 11 Nov 90 20:40:32 GMT
References: <17167@shlump.nac.dec.com>
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In article <17167@shlump.nac.dec.com> nadkarni@ashok.dec.com (Ashok P. Nadkarni) writes:
>I am porting an application to Windows 3.0 that makes extensive use
>of linked lists. Storage needs are sufficiently large that I have
>to use global memory. I know just enough about Windows programming that
>I realize it is Bad Thing to leave memory locked. However, unlocking means
>that all the links pointing to the prev/next list elements are garbage
>every time Windows moves memory around. Is there a solution to this problem?


Here are two possibilities: either keep handles, not pointers in the
linked list, and lock them when you need them. However this does make
traversing the linked list a bit messy, if you do that a lot, locking
and unlocking as you move along. (sadness). 

The other possibility; if your program is only going to be run on
386's (in enhanced mode), it doesn't hurt to keep everything locked
down, because the hardware can still move things about without the far
pointers changing. I ported a large system to windows this way; it is
enough to replace malloc(x) with GlocalLock(GlobalAlloc(GMEM_MOVEABLE,x));

Joel Spolsky
spolsky@cs.yale.edu                                     Silence = Death